So say electrician stage 1. After a four week course you can go out add a socket to a circuit, inside or out in any room or location but perhaps only on 230v domestic, do repairs and carry out the appropriate tests and provide the paperwork. For some this would be all they want to do.
Electrician level 2, six week course.Complete rewires and fault finding, domestic only. Again for some thats all they want so would now stop training at this point. Their cards would state this is what they can do (bit more than a domestic installer grade i think) so they cant go off into 410v or industrial or commercial.
Level 3 410v systems 3 phase and so on. At successful completion of each stage you get a competant person certificate from the training body.